Three-dimensional (3D) printing (e.g., additive manufacturing) is a process for making a three-dimensional object of any shape from a design. The design may be in the form of a data source such as an electronic data source, or may be in the form of a hard copy. The hard copy may be a two-dimensional representation of a 3D object. The data source may be an electronic 3D model. 3D printing may be accomplished through an additive process in which successive layers of material are laid down one on top of another. This process may be controlled (e.g., computer controlled, manually controlled, or both). A 3D printer can be an industrial robot.
3D printing can generate custom parts. A variety of materials can be used in a 3D printing process including elemental metal, metal alloy, ceramic, elemental carbon, or polymeric material. In some 3D printing processes (e.g., additive manufacturing), a first layer of hardened material is formed (e.g., by welding powder), and thereafter successive layers of hardened material are added one by one, wherein each new layer of hardened material is added on a pre-formed layer of hardened material, until the entire designed three-dimensional structure (3D object) is layer-wise materialized.
3D models may be created with a computer aided design package, via 3D scanner, or manually. The manual modeling process of preparing geometric data for 3D computer graphics may be similar to plastic arts, such as sculpting or animating. 3D scanning is a process of analyzing and collecting digital data on the shape and appearance of a real object (e.g., real-life object). Based on this data, 3D models of the scanned object can be produced.
A number of 3D printing processes are currently available. They may differ in the manner layers are deposited to create the materialized 3D structure (e.g., hardened 3D structure). They may vary in the material or materials that are used to materialize the designed 3D object. Some methods melt, sinter, or soften material to produce the layers that form the 3D object. Examples for 3D printing methods include selective laser melting (SLM), selective laser sintering (SLS), direct metal laser sintering (DMLS) or fused deposition modeling (FDM). Other methods cure liquid materials using different technologies such as stereo lithography (SLA). In the method of laminated object manufacturing (LOM), thin layers (made inter alia of paper, polymer, or metal) are cut to shape and joined together.
The energy beam may be projected on a material bed to transform a portion of the pre-transformed material to form the 3D object. At times, debris (e.g., metal vapor, molten metal, or plasma) may be generated in the enclosure (e.g., above the material bed). The debris may float in the enclosure atmosphere. The floating debris may alter at least one characteristic of the energy beam (e.g., its power per unit area) during its passage through the enclosure towards material bed. The debris may alter (e.g., damage) to various components of the 3D printing system (e.g., optical window). Some existing 3D printers establish cross flow of gas to reduce the debris in the enclosure atmosphere. However, some of these cross-flow solutions cause undesirable gas flow structures (e.g., stagnation, recirculation of gas within the enclosure that may lead to a steady state) that do not completely solve the debris related issues. It may be desirable to establish a gas flow solution that avoids the undesirable gas flow structures and allows removal of debris from the enclosure atmosphere.
At times, during the 3D printing, various material forms become gas-borne. The material forms may compromise (e.g., fine) powder or soot. Some of the gas-borne material may be susceptible to reaction with a reactive agent (e.g., an oxidizing agent). Some of the gas-borne material may violently react (e.g., when coming into contact with the reactive agent). At times, it may be desirable to provide low leakage of the reactive agent (e.g., oxygen in the ambient atmosphere) into one or more segments of the 3D printer. At times, it may be desirable to isolate the interior of one or more segments of the 3D printer from a harmful (e.g., violently reactive) level of the reactive agent (e.g., that is present in the atmosphere external to the one or more segments of the 3D printer). At times, it may be desirable to preserve a non-reactive (e.g., inert) atmosphere in at least one segment of the 3D printer (e.g., before, during and/or after the 3D printing).
At times, gas-borne material may be collected within a filtering mechanism. The gas-borne material may violently react (e.g., ignite, flame and/or combust), when exposed to an atmosphere comprising the reactive agent (e.g., an ambient atmosphere comprising oxygen). It may be desirable to incorporate a filter mechanism that is separated (e.g., isolated) from an external (e.g., ambient) atmosphere comprising the reactive agent. It may be desirable to incorporate a filter mechanism that maintains an inert interior atmosphere around the filter, at least during the filtering operation and/or disassembling of the filter from the filtering mechanism. It may further be desirable to facilitate an uninterrupted exchange of the filter in the filtering mechanism, for example, in order to facilitate continuous separation of gas-borne material from the recirculating gas in at least one or more segments of the 3D printer during the 3D printing, for example, when the filter clogs and requires exchange and/or refurbishing. The present application describes ways of meeting at least some of these desires.